<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<script>
		//js中定义变量var 
			var x =10;
			var y =20;
			
			console.log(x+y);
			var a= 10,b=20;
			console.log(a*b)
			
			var x=100,y=2;
			console.log(x)//js语言非常灵活 再次声明值会被覆盖
			
			console.log(typeof(x))
			
			var x ="accc"//类型可以改变，Java中不行
			console.log(x)
			console.log(typeof(x))
		</script>
	</head>
	<body>
	</body>
</html>
